Search results
Results from the WOW.Com Content Network
The frequency range handled by an amplifier might be specified in terms of bandwidth (normally implying a response that is 3 dB down when the frequency reaches the specified bandwidth), or by specifying a frequency response that is within a certain number of decibels between a lower and an upper frequency (e.g. "20 Hz to 20 kHz plus or minus 1 ...
An example is a common sound amplification system with a microphone, amplifier and speaker. When the microphone is in front of the speaker, we hear an annoying whistle. This whistle is generated without extra contribution from the sound source, and is self-reinforced and self-sufficient while the microphone is somewhere in front of the speaker.
A simple example is the light of a conventional light bulb being modulated at twice the line frequency. Some lock-in amplifiers also allow separate measurements of these higher harmonics. Furthermore, the response width (effective bandwidth) of detected signal depends on the amplitude of the modulation.
The intermodulation between frequency components will form additional components at frequencies that are not just at harmonic frequencies (integer multiples) of either, like harmonic distortion, but also at the sum and difference frequencies of the original frequencies and at sums and differences of multiples of those frequencies.
If the frequency deviation is held constant and the modulation frequency increased, the spacing between spectra increases. Frequency modulation can be classified as narrowband if the change in the carrier frequency is about the same as the signal frequency, or as wideband if the change in the carrier frequency is much higher (modulation index ...
Audio stereo power amplifier made by McIntosh The internal view of a Mission Cyrus One hi-fi integrated audio amplifier (1984) [1]. An audio power amplifier (or power amp) amplifies low-power electronic audio signals, such as the signal from a radio receiver or an electric guitar pickup, to a level that is high enough for driving loudspeakers or headphones.
Unless θ (t) is a constant, the point in time t s at which the phase is stationary will vary according to the instantaneous frequency ω s. Expressing the difference between (ω s-ω 0).t and θ (t) as a Taylor series about the time t s, but discarding all but the first three terms (of which the second term is zero, here), the Fourier integral ...
However, since even for zero frequency difference there may exist initial states of loop such that cycle slipping may take place during the acquisition process, the consideration of initial state of the loop is of utmost importance for the cycle slip analysis and, therefore, Gardner’s concept of lock-in frequency lacked rigor and required ...